Delmars Unit 15 Alternating Current

What is the average voltage of a full-wave rectified 240 V RMS AC voltage? 216.17 V 276.32 V 332.75 V 252.88 V

216.17 V

What is the RMS value of an AC voltage that has a 480 V peak? 453.53 V 278.72 V 339.46 V 305.76 V

339.46 V

What is the peak voltage of a 277 V RMS AC voltage? 695.90 V 391.68 V 576.45 V 434.85 V

391.68 V

Both AC and DC can be transformed. True False

False

The square root of the mean of the square of the instantaneous currents is known as the _____. average peak peak-to-peak RMS

RMS

If an AC waveform is rectified and converted into DC, the voltage value that results is the _____ value. effective peak-to-peak peak average

average

Each complete waveform of 360° is called a _____. hertz frequency rotation cycle

cycle

A term used to indicate the same value as the RMS value is the _____ value. peak-to-peak effective average peak

effective

The number of cycles completed in one second is called a _____. hertz frequency rotation cycle

frequency

Frequency is measured in _____. voltage hertz watts amperes

hertz

The maximum point of a waveform is called the _____. peak-to-peak effective RMS peak

peak

What type of load contains pure resistance? capacitive reactive inductive resistive

resistive

When AC voltage is rectified and converted into DC, the resulting waveform is normally not pure, flat DC. The pulses that occur are called _____. harmonics cosines peaks ripples

ripples

Rotating machines normally produce a waveform called a _____ wave. cosine linear sine pulsating

sine

What is the most common of all AC waveforms? cosine triangle sine pulsating

sine

The_____ effect occurs when AC induces eddy currents into the conductor, which cause the electrons to be repelled toward the outer surface of the conductor. skin resistance insulation phasing

skin

To help overcome the problem of skin effect in high-frequency circuits, conductors with a large amount of _______________ must be used.

surface area

In a DC circuit, the product of volts times the amperes is called the _____ power. apparent reactive inductive true

true

What is the unit of measure for the power delivered to the load in a DC circuit? watts hertz volt-amperes VARs

watts

The amplitude of a waveform is measured from _____. zero to the RMS level zero to the highest value obtained in either direction zero to the effective level peak-to-peak

zero to the highest value obtained in either direction

When current rises and falls at the same rate as the voltage and reverses the direction of flow when the voltage reverses polarity, the current is said to be _____ with the voltage. in phase in lagging phase out of phase in leading phase

in phase

What type of AC waveform features voltage rising at a constant rate with respect to time? sine linear pulsating cosine

linear

Square waves are generally produced by electronic devices called _____. rectifiers converters alternators oscillators

oscillators